Digester.



No. 881,888. lv PATBNTED MAR. 17, 1908. W. H. A'I'WOOD.

DIGESTBR.

APPLIoATIoN FILED PEB. 4, 1901.

More specifically* u .-inventlonis' tosu fof adiesting or-bleaching liquor orsteam WILLIAMRATWQOD', or LINCOLN, NEBRASKA.

l 'irreiesiases4 A Specification of Letters Patent.

Patented March` 17, 1908.

Application mea rama-ya, 1907, serial No. 355,619.

'- i Be it 'known that I, WIiLIAMl-I. A'rvvoon,

afcitizen of the United States, vandresident ofv Lincoln, in the county .of Lancaster and i State of Nebraska, have invented certainnevv and'useful Improvements in Digesters, 1

ofwhich the followlngis a full, clear, and eXT ,act specification. v

- vention relates to improvements in digesters'especially adapted for thereduction of iibers to pulp for thefpurioses 4of, produc'- -ing paper sii-Jock,V and in whi' there is a continuous circlilationofa heated alkaline. soluf "tion, or other liquorunder pressure 'through a :15

fibrous mass contained Within the digester, but which is, also adapted for thebleaching of fiber by subjection to fa' bleaching solution either hot or coldlindeipressure. v

The rime object 'of liquor o'r may, be steam to 'the -iiber under treatment Vin av digester in such a manner that the mass thereof will thereby' be 'maintained' in a loose condition that the-individual iibersj l. willbe promoted ,"and that the necessity for" mechaniealstirrers `and the revolving of the digester are entirely dispensed with.

stated, the object of .my ject the ber to the force and obli uelyupwardly the massvt ougltjet `01'1-` directe 'outwardly `35 from the centeno fices",1t he position ofvvhich` with reference'to 1 the mass ,may beconstantly' shifted.`

Afurther object of, r` r ly invention is to sub'-4 ject the: mass ofiiber to jets of liquor .or steam 40 vdirected from .the -center of .the `mass outf wardly and upwardly with `such`foree1that imyact thereofwill thelmasscony atfrequent intervals and maintain it in a suflicientlyloosened conditionfor sublj'jecting' -the individual` fibers vtherein to -a rapid current of-li uor or'steam which is cor- V\'restpondingly quie y discharged 'therefrom an correspondingly hasten. t tion or bleahing of the iber, as may be. v 150 Another; object ofmy-.inveution is' to ,pro-

substantially axially theret ough and con# A nected with 'simpleand effective propelling' jmechanis'mfor revol' axis .(lif there during my invention broadly 5 stated-1s 'todeliver the digesting or bleachingA 'the upper end of the digesteris a sulply plpe the digeetery and which durin its continue' disintegra-- vide a digesterftvith a suply. ipe pass' E' P mg means of the llquor'or a' portion ,fma'ss, the circulation ofthe liquor through the digester and its discharge therefrom.

'v With these ends in vievsT my invention consists-in certain features of novelty in the construction, combination and arrangement vof parts, -by Which,the said objects and certain other objects hereinafter appearing/are 'at-- tained, all as flly described With reference to the accompanying-drawings, and more -particularly pointedgoutin the claimsl `9 5 r 'In said drawingsz- Figure 1 illustrates 'a longitudinal vertical section thr'ou h a 'div gesterembodyingmyinvention in w ch the .suply *or delivery pipe and,the\turbi ne or ot er motor is shown partlyn section. Fig. so 2,'atransverse section through the delivery or supply l) ipe', illustrating amodied means rotat' said 'i e. y

Simuilr nunlielifals of referenceindicate the Afordischarging the liquor therefrom and for I same parts in the figures of the drawingl g 3 indicates the body of the .outer shell of a digester and 4 and- 5 the upper and` lower, head ends thereof, which di ester is shown of cylindrical form vbut may e of any other form and which, as*v usual, is 'constructed ofl. l metal of.- suiiicient .strength 4towithstand considerable; pressure. "r .j Projecting through and i slightly ibeyqnd 6 through which tlie liquor is intro uced to ous circulation 'therethrough',-is dihrged through a ipe v7 vv connected with thel'ower end thereo which pes 6ai1dw7 areres tively provlded lWit ordinary stop-colo and 9 for regulatingv the suipliy and 'dis-V charge of' the. liquor employe fiel',-

" f Within the bod' of the -digester is .anannular-'chamber 10\y ormed by'a sliell 1 of less diameter than "said bod and-whichextends a' S'llOllil 0W thdupper of the digesterto 'the owerhead thereofwhich, 11o j vannularchamber is o en at both ends., s

Thenpper end of t e inner shell is closedas near as may beby' awire orother screen m, th-'digesl may be continuously discharged therefromy through said man-hole, and if desired there may be towards the upper end in the side of the digester, afurther man-hole` 17 or vas a substitute for the man-hole ,14, all of which,

man-holes are providedwith the usual closing means therefor for resisting the internal pressure of the digester.

` The inner shell 11 is provided with a number of openings closed with screens 18 which extend at intervals` entirely around the digester and at such distances one above the other-as to enable the liquor to freelV discharge into the annular chamber 10 a ter it has passed through the fiber and whencethe liquor discharges into the bottom of the digester and out through the discharge pipe 7.

Supported b the bottom end 5 of the digester 1s a brac et bearing 19 supporting the vlower .end of the tube 20, which extends u wardlyA through the digester and preferab y axially thereof to an inner projecting end 21 of the su plyj ipe 6 about which it is free to turn, althoug preferably fitting the same quite closel the lower end of the tube 20 beingvclose `and yterminating-in a cone 22 projecting into the bearing 1,9, but any other ordinary form of support may be employed for the'tube so long as it is ,adapted to both su port and permit the tubeto freely re.-

described. l o

As a means for actuating the tube' 20, I have shown secured thereto, towards its upper end and above the screen 12, vanes or vo ve when actuated by means hereinafter Wings 23 of any suitable character, as for exam le such as are commonly employed in tur ine or other water wheels.

Wings 23 may be screwed into the tube 20 as shown or rigidlysecured. thereto by any other suitable means andare-confined within -a casing 24, provided near its bottom with a s eries of openings 25. and with an annular- 'opening 26 in its bottom adjacent the tube 20 for the discharge of li ruor or steam supplied througha, pipe 27 to tlievanes and whereby the liquor-or-stearn employed for actuating the vanes, may pass dlrectl bothV into-the inner shell 11 and the annu ar chamber 10, the supply and therefore the Ipressure of said liquor or vsteam being regulated by an ordinarystop-'cock2'8 inthe pipe 27. Tube .20 has a -series of perforations 29 which terlminata Within the connes ofthe screens 12 and 13, the arrangement and `direction of which, and particularly the latter, are important features of my invention. In other words said perforations 29 are located on a spiral line extending lengthwise of the tube 2O and at such intervals that the planes of the discharge of the liquor or steam therefrom are quite close the one to the other and which is made possible throughout the mass of iberA owing to the revolution of the tube, While at the same time the force required for discharging the contents of the tube with violent impact in vand againstl the ber is reduced to a minimum.

vFor the purposes of utilizing the discharge of the liquor through the perforations for maintaining the fibrous mass in a loose condition, a number of the perforations 29 and ma be all of them, have an upward incline as indicated at a`, but as indicated respectively at b and c some of these perforations may be horizontal and others inclined downwardly and in this connection it may be observed that wherethe walls of the tube are not of sufficient thickness to give the desired direction to the discharging jets, internal nipples maysbe employed.

shown in Fig,y 1 the perforated supply tube is rotated bythe impact of liquor under ressure from. the ipe 27 against the wing ut it Will be no su stantial departure from my invention to connect the perforations in l the tube with bent tubular arms 30 (see Fi 2),as a means for rotatin the tube throu the change of direction o thec'urrent of t e fluid or steam discharging therefrom, which arms may. also have their outer ends turned upwardl forgiving such direction to the jets as will ift", and thereby loosen the brous mass and so also said means of propulsion may .be used as an auxiliary to the propulsion structure in rotating the tube, bui'in .practice under ordinary circumstances these bent arms are dispensed with for the reason that to some extent they gather the fiber where the mass is somewhat dense and thereby tend toretard the rotation of the tube and therefore the digesting'of the fiber. 4 f

As a means for deter the velocity of rotation of the supply pipe uring the operation of the digester, a pro'ecting pin Slis.

secured to the tube towar s its upper end and 1n the path of this in and secured to the inner side of the hea of the digester, is a.

straight spring, which by itsL intermittent engagement with the `pin during the' revolutlon of the tube, serves. to c/ause a clicking sound indicatingbthe rapidity of the movement ofthe tu efbut any other suitable means ada ted` for `that pose may be employed wit out a substantie Adeparture from the spirit of my invention.

Insoperationfthe supply pipes 6 and 27 and the dischargepip 7'are connected with 'a coil, in the usual manner, with some heating 60- `me1i't, 'for Ait'broadlyincludes any'means 'y y apparatus and the supply pipes are connected ceases with a force pump or motor and by means of which the liquor is conducted through the digester, not only under the pressure of heat but bythe physical-act on of the pump., with the result that it is dish-arged from the revolving tube with consi erable force' andin a Aseries of comparativelysmalljets, the sup- Vply of the liquor however being'suflicient to `ingtliro'ugh t e digester and out throu h the maintain the di ester continuously filled with the li uor or leaching iluid, as may be. After t e iiber has been introduced through and the supply manhole closed, the valve of the supply pipe andmay be also'of the supl pipe 27 are opened until the digester is hib of hot li uor and continuously circulatdischarg'e pipe' 7 andthence throug the heater, and when such circulation is once well established 'then the valve in the pipe 27 is utilized as far as may be necessary, to regulate the force of its discharge against the wings of the motor and thereby maintain the rotation of the tube at the desired or necesvelocityg/ the liquor orifices inthe su ply pipe, so` much of it asis directed upward y thro h the inclined perforations, operates throug its forceto lift the entire mass at frequent intervals suiieiently tomaintain the'iiber uniformly loosenedy throughout the entire mass, with the result v that without an excessive force, the jets are those lying next the walls of the` ii'inershells and in which respect the jets are substantiallyaidfed by reason of the screen openings 18 be directed with quite a violentimpact throughoutfthe individual fibers and particularly cause of the outward current produced in the mass in lthe direction taken by the`jets,whicli current moreover o erates- .to subject the fibers to theaction o a continuous fresh su s ply of liquor and promotes the rapidity of t circulation of .the -li uor throughout the di" gester,v thereby su 'stantially materially 'shortening the time for digesting-the fiber or bleaching it, as may be.v

The revolving of the su ply-tube enables the spiral 'arrangement oft e'jet orifices and a corresponding reduction in the number otherwise' re u ired andthe simultaneous injection of the liquor at different points andin parall lel planes in close proximity to Veach other, j for it will be 'observedthat if thesame num'- berof orifices encircle the tube parallel .-rings, either the distance between their planes of discharge be lincreased 'or 'else' the same iiberwouldnot be'as, frequently subjected to their dis harge. A' My invention however is not limite to the spiral arran ewhich the' liquor supplied to the digester is under pressure and dischar ed into the iber atfrequent intervals both'm'timev and loca,-v

tiqn in jets rotated about a common axis;

' as described.

tions, and means forrevolving sai f substantially as described. discharges through the jvetv Having described my meeneem-'wha I claim as new and desire, to-,secureby Letters l Patent, is:

Y 1. A digester receptacle, 'combination f With a revolving perforated supply member A wholly confined within the receptacle, subr stantially as described.` i. i

2f Adigester receptacle, in combination l with a supply member and rovided with dise charging perforation, an wholly confined within the' receptacle. and means in thereceptacle revolving said member, substantially as described.

3. A digester receptacle, .in combination-` with a supply member lprdvided with-.discharging erforations in s iral arrangement,` and who y confined wit 'n the receptacle and means and wholly located in the receptacle for revolving said member, substantially with a supply member projectedl axially therein and provided with a series of inclined perforations through which the liquor is d ischarged upwardly at an obli ue angle to said member, and means for revo ving the same, substantiallyas described. l if 7. A digester receptacle, in combination with a supply tube provided with a'series of' jet orifices extending upwardly at anoblique -105 angle theretle, means for su portingsaid Supply tube'fronrthe bottom ol the digester, and

l means for revolving said supply tube onf its vown axis, substantiallyasdescribed.

8'. A 'digester receptacle, `in combinationllo with 'a revolvingtube projecting axially and i V journaled therein, and a' seriesof` upwardly"A linclined discharge orifices in 'spiraly arrangement lengthwise of said tube, and means for revolving said tube, substantially as described.

Q/.JA digester,eomprisinginjcombinatiop'-l' receptacle, means for continueusly gupplymg 4 f anddischarging liquor therefrom, means for delivering liquor to said receptacle in a series 1 20 'ojetsv projected. alng lines extending up-j,

wardly and'outwardly from the axis-thereof, i Q and means'for'continuously bodily revolving v said jets around said axis, substantially 'as described.I

10. 'Aldigesten comprisii'igeiiriconibinatien'' anoutershellv or body., an inner shellformin an open-endannular chamber adjacent sai body portion, a series of screen openings at 1 member the-length of the Vinn-a Shen, a im she suply tube projected through said inner and provided with .a series' of inclined discharge orifices, and means for revolving saidsu ply tube, substantially as described.

11. n a digester, com rising in combination, an inner and outer s ell or body, an inner shell rovidin an open end annular chamber a jacent t e outer shell, a series of screen openings between the inner'shell and said chamber, a supply tube rovided with a series of spirally arranged dlscharge orices inclined upwardly and outwardly with reference to the axis-of said tube and towards 'said screen openings, and means revolvin said supply tube through the force of the 'quor- 

